KR102474917B1 - Self-interference cancellation method and system by a node in a wireless communication system - Google Patents

Abstract

Embodiments herein provide a method for decoding a signal received by a node in a wireless communication system. The method comprises receiving a signal from a first user equipment (UE), wherein the received signal comprises a set of preambles, each preamble of the set of preambles being equal to at least one preamble in a preamble structure. -; and obtaining a composite signal comprising a self-interference signal, wherein the self-node signal is known at the node. The method also includes determining a self-interference channel estimate using the composite signal and decoding the received signal by removing the self-interference signal from the received signal based on the self-interference channel estimate. Include steps.

Description

Self-interference cancellation method and system by a node in a wireless communication system

Embodiments herein relate to wireless communication. More particularly, it relates to a method and system for decoding a signal received by a node in a wireless communication system. This application is based on and claims priority from Indian Application No. 201741007911 filed on March 7, 2017, the disclosure of which is hereby incorporated by reference.

In general, components of a wireless communication system, such as nodes, support an in-band full-duplex communication mode. The in-band full-duplex communication mode involves a node simultaneously transmitting and receiving signals from a plurality of user equipments (UEs). However, a challenge in achieving in-band full-duplex communication is to effectively decode a signal received by a node in the presence of self-interference generated by the node.

Existing self-interference suppression techniques in the in-band full-duplex communication mode provide self-interference suppression that limits the application of the in-band full-duplex communication mode in wireless communication systems. In addition, in order to cancel the self-interference, accurate estimation of the self-interference channel and consequent cancellation of the self-interference are required.

The above information is presented as background information to aid the reader in understanding the present invention. Applicants have not determined and are not making any assumptions as to which of the foregoing may be applicable as prior art to the present application.

A primary objective of the embodiments herein is to provide a method and system for decoding a signal received by a node in a wireless communication system.

Another object of embodiments herein is to provide a received signal comprising a set of preambles, each preamble equal to at least one preamble in a preamble structure.

Another object of the embodiments of the present specification is to cancel a received signal in self-interference channel estimation using the same preambles in the preamble structure.

Another object of embodiments herein is to determine a self-interference channel estimate.

Another object of embodiments herein is to decode a received signal by removing a self-interference signal from the received signal.

Another object of embodiments herein is to remove a self-interference signal from a received signal using self-interference channel estimation.

Another object of embodiments herein is to use a filter suitable for determining a self-interference channel estimate.

Another object of embodiments of the present specification is to provide a method for estimating a self-interference channel in digital, analog and RF domains.

Accordingly, embodiments herein provide a method of decoding a signal received by a node in a wireless communication system. The method comprises receiving a signal from a first User Equipment (UE), wherein the received signal includes a set of preambles, each preamble being equal to at least one preamble in a preamble structure. and obtaining a composite signal comprising a self-interference signal, wherein the self-trunk signal is known at the node. The method also includes determining a self-interference channel estimate using the composite signal and decoding the received signal by removing the self-interference signal from the received signal based on the self-interference channel estimate. Include steps.

Accordingly, embodiments herein provide a node for decoding a received signal in a wireless communication system. The node includes a processor, a memory coupled to the processor, and a transceiver coupled to the processor and the memory. The transceiver is configured to receive a signal from a first user equipment (UE), the received signal comprising a set of preambles, each preamble being equal to at least one preamble in a preamble structure, wherein the transceiver is configured to self-interfere and obtain a composite signal comprising a signal, wherein the self-interference signal is known at the node. Also, the transceiver is configured to decode the received signal by determining a self-interference channel estimate using the composite signal and based on the self-interference channel estimate, canceling the self-interference signal from the received signal. do.

These and other embodiments of the embodiments herein will be better appreciated and understood when considered in conjunction with the following description and accompanying drawings. It should be understood, however, that the following descriptions, while indicating preferred embodiments and numerous specific details thereof, are provided by way of example and not limitation. Within the scope of the embodiments herein, many changes and modifications may be made without departing from the spirit of the present specification, and the embodiments of the present specification include all such modifications.

BRIEF DESCRIPTION OF THE DRAWINGS The invention is illustrated in the accompanying drawings, wherein like reference characters throughout the drawings indicate corresponding parts in the various drawings. Embodiments of the present specification will be better understood from the following description with reference to the accompanying drawings.

1 is a diagram illustrating an in-band full-duplex wireless communication system having a node and a plurality of UEs for self-interference cancellation at the node, according to embodiments disclosed herein.
2A is a block diagram showing various elements of a node, according to embodiments disclosed herein.
2B is a block diagram showing various elements of a transceiver of a node, in accordance with embodiments disclosed herein.
3A is a diagram showing a time domain packet structure of a signal received by node 200 including a set of preambles, in accordance with embodiments disclosed herein.
3B is a diagram illustrating a process of obtaining a composite signal using a signal received over the air and a self-interference signal according to embodiments disclosed herein.
4 is a flowchart illustrating a method of decoding a signal received by a node in an in-band full-duplex wireless communication system according to embodiments disclosed herein.
5 is a block diagram showing various elements of a user equipment (UE), in accordance with embodiments disclosed herein.
6 is a flowchart illustrating a method for transmitting a signal by a UE in an in-band full-duplex wireless communication system according to embodiments disclosed herein.
7 is a diagram showing self-interference channel estimation according to embodiments disclosed herein.

From now on, various embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. In the following description, specific details, such as detailed configuration and components, are merely provided to facilitate a general understanding of these embodiments of the present disclosure. Therefore, it will be apparent to those skilled in the art that various changes and modifications of the embodiments described herein can be made without departing from the scope and spirit of the present disclosure. Also, descriptions of well-known functions and constructions are omitted for clarity and conciseness.

Also, as some embodiments may be combined with one or more other embodiments to form new embodiments, the various embodiments described herein are not necessarily mutually exclusive.

As used herein, the term “or” is referred to as non-exclusive or unless otherwise indicated. The examples used herein are merely to facilitate understanding of how the embodiments herein may be practiced and to additionally enable a person of ordinary skill in the art to practice the embodiments herein. Accordingly, the above examples should not be construed as limiting the scope of the embodiments herein.

The terms "first" and "second" in this specification are used only for labeling purposes and may be used interchangeably without departing from the scope of the embodiments.

As used in the description herein, the term “node” refers to any device or equipment that supports in-band full-duplex wireless communication, such as, for example, a base station (BS), user equipment (UE), Wi-Fi access point, transceiver, and the like. includes

Accordingly, embodiments herein provide a method of decoding a signal received by a node in a wireless communication system. The method includes receiving a signal from a first user equipment (UE), wherein the received signal includes a set of preambles, each preamble being equal to at least one preamble in a preamble structure, and a self-interference signal. obtaining a composite signal comprising, wherein the self-interference signal is known at the node. The method also includes determining a self-interference channel estimate using the composite signal and decoding the received signal by removing the self-interference signal from the received signal based on the self-interference channel estimate. Include steps.

In one embodiment, the self-interference estimate is determined by finding differences between identical preambles in the composite signal and using the resulting difference samples.

In one embodiment, the self-interference estimate is determined using an adaptive filter. Examples of adaptive filters include least mean square filters, recursive least squares filters, and the like.

In conventional in-band full-duplex wireless communication methods and systems, in-band full-duplex two-way simultaneous communication does not work because of self-interference encountered by the node due to simultaneous reception and transmission. Also, self-interference degrades the decoding of the received signal at the node.

In conventional methods and systems, a transmitted signal is used along with the self-interference signal to generate a copy of the self-interference signal, which is subtracted at the receiver to suppress the self-interference.

Unlike conventional methods and systems, the proposed method involves using a set of symmetrically identical preambles in the received signal to cancel the received signal component in the composite signal. Also, the composite signal is used to determine the self-interference channel estimates.

Unlike conventional methods and systems, the proposed method uses the self-interference channel estimates to remove the self-interference signal from the received signal while decoding the received signal.

Unlike conventional methods and systems, the proposed method removes the received signal component from the composite signal and determines the self-interference channel estimates, ensuring a better channel estimate. Also, the self-interference channel estimates are used to cancel the self-interference channel while decoding the received signal.

Unlike conventional methods and systems, in the proposed method, the self-interference channel estimation is performed based on a composite signal that does not have the received signal component or has significantly reduced components of the received signal.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring now to the accompanying drawings, and specifically to FIGS. 1 to 7, where like reference characters collectively indicate corresponding features throughout the accompanying drawings, preferred embodiments are shown.

1 shows an in-band full-duplex wireless communication system 100 having a node 200 and a plurality of UEs for self-interference cancellation at the node 200, according to embodiments disclosed herein.

In the in-band full-duplex wireless communication system 100, the same frequency spectrum is used by the node 200 to simultaneously transmit and receive signals. In other words, the node 200 can transmit communication signals to a plurality of UEs (eg, a first UE 102a and a second UE 102b) simultaneously in the same frequency spectrum and transmit communication signals to the plurality of UEs. (In other words, it can be received from the first UE 102a and the second UE 102b). However, the possibility of using the same frequency spectrum for simultaneous transmission and reception results in interference issues that need to be addressed. The main type of interference that can be created if the same frequency spectrum allows both transmitting and receiving signals is self-interference, where a node transmitter interferes with its own receiver. Moreover, the suppression and generation of the self-interference signal may be performed partly in the analog domain and partly in the digital domain. Also, since the self-interference channel changes according to the surrounding environment, periodic estimation of the self-interference channel is important to suppress the self-interference. Moreover, a preferred channel estimation method is one that can efficiently estimate the self-interference channel in the presence of the received signal to avoid excessive overhead.

Referring to FIG. 1 , a representative in-band full-duplex wireless communication system 100 includes the node 200 and UEs, namely the first UE 102a and the second UE 102b. The node 200 receives a signal from the first UE 102a and transmits a signal to the second UE 102b. However, when the node 200 receives an incoming signal from the first UE 102a, the node 200 also simultaneously satisfies transmitting an outgoing signal to the second UE 102b. The signal transmitted to the second UE 102b creates self-interference to the processing of the signal received from the first UE 102a at the node 200 . For the node 200 to be able to effectively decode the incoming signal from the first UE 102a, the self-interference must be suppressed.

The proposed method and system provide a self-interference cancellation technique. The signal transmitted by the first UE 102a is provided with a set of preambles. The set of preambles appear in pairs, and each preamble is identical to the other preamble in the preamble pair, so it is symmetrical. A symmetrical preamble structure is used to completely cancel the received signal components from the self-interference channel estimates, and the self-interference estimates are additionally used to decode the received signal. Furthermore, the preamble may refer to any pair of IQ sample sequences, and the IQ sample sequences may be time separated. Furthermore, the location and length of the sequences must be known at the node. For example, the sequences may include a cyclic prefix of an OFDM system such as LTE, 5G new radios, Wi-Fi (802.11), a xxxxxx preamble of a Wi-Fi system, and the like.

At the node 200, the obtained composite signal is a received signal (ie, the received signal from the first UE 102a) and a self-interference signal (ie, the second signal received by the node 200). signal transmitted to the UE 102b). Also, the composite signal is used to obtain the self-interference channel estimates. The self-interference channel estimates are used to cancel self-interference in the received signal while decoding the received signal.

2A is a block diagram showing various elements of a node 200, according to embodiments as disclosed herein.

Referring to FIG. 2A , the node 200 may include a transceiver 210, an encoder/decoder 220, a processor 230, and a memory 240.

In one embodiment, the transceiver 210 may be configured to receive a signal transmitted to the node 200 by the first UE 102a. The received signal includes encoded data with a symmetric preamble structure (310). The symmetric preamble structure 310 includes a set of preambles represented by a preamble pair (ie, any pair of identical IQ sample sequences). Also, each preamble in the preamble pair is symmetrically identical to consecutive preambles. In addition, the preamble structure is described with reference to FIG. 3A in the latter part of this description.

Additionally, the transceiver 210 may be configured to transmit a signal from the node 200 to the second UE 102b. The transceiver 210 of the node 200 simultaneously transmits and receives signals to and from the UE.

In one embodiment, the encoder/decoder 220 may be configured to encode data to be transmitted to the second UE 102b. The encoder/decoder 220 may also be configured to decode a signal received from the first UE 102a to extract data from the received signal.

In one embodiment, the processor 230 interacts with hardware components such as the transceiver 210, the encoder/decoder 220, and the memory 240 in the node 200 to cancel self-interference. and to decode the received signal at the node 200.

In one embodiment, the memory 240 may include non-volatile storage elements. Examples of such non-volatile storage elements may be magnetic hard disks, optical disks, floppy disks, flash memories, or forms of Electrically Programmable Memory (EPROM) and Electrically Erasable and Programmable Memory (EEPROM). Also, the memory 240 may be considered a non-transitory storage medium in some examples. The term "non-transitory" may indicate that the storage medium is not implemented as a carrier wave or a propagating signal. However, the term “non-transitory” should not be interpreted as saying that the memory 240 is not removable. In some examples, the memory 240 may be configured to store a larger amount of information than the memory. In certain examples, the non-transitory storage medium may store data that may change over time (eg, in random access memory (RAM) or cache).

2B is a block diagram showing various elements of a transceiver 210 of the node 200, according to embodiments as disclosed herein.

Referring to FIG. 2B , the transceiver 210 may include a transmitter 202, a receiver 204, a self-interference estimator 206, and a self-interference canceller 208.

In one embodiment, the transmitter 202 may be configured to transmit signals from the node 200 to a plurality of UEs. The transmitter 202 may also include a digital-to-analog converter (DAC) to convert a digital signal to an analog signal prior to transmission. In addition, the uplink frequency converter may convert the analog signal into a high frequency band RF signal and transmit the analog signal to a power amplifier, and the power amplifier may amplify the high frequency band RF signal so as to be transmittable.

In one embodiment, the receiver 204 may be configured to receive signals from multiple UEs. The receiver 204 may also include an analog-to-digital converter (ADC) that converts the received analog signal to a digital signal prior to processing. The downlink frequency converter may convert the high frequency band RF signal into a baseband signal.

In one embodiment, the self-interference estimator 206 may be configured to determine a self-interference channel estimate. The self-interference estimator 206 obtains a composite signal. The composite signal is obtained when the received signal and the self-interference signal (ie, the transmitted signal) are combined over the air. The self-interference signal is a signal transmitted by the node 200 to the second UE 102b, and the self-interference signal is known at the node 200. The self-interference estimator 206 may also include an adaptive filter that determines the self-interference channel estimate by using a known transmit signal and calculating the difference between successive pairs of composite signal pairs. In one example, the adaptive filter may be one of a minimum mean square filter, a recursive least squares filter, and the like. The adaptive filters continuously change the estimated channel coefficients by tracking them from SI1-SI2 and/or SI3-SI4. The obtained self-interference channel estimate either has no component of the received signal or significantly reduces the component of the received signal. Absence of any component of the received signal in the self-interference channel estimate provides a better channel estimate. Also, the number of components of the composite signal required for channel estimation does not depend on the strength of the received signal.

In one embodiment, the self-interference canceller 208 may be configured to cancel a self-interference signal in the received signal using the self-interference channel estimate.

3A shows a time domain packet structure of a signal received by node 200 including a set of preambles, in accordance with embodiments as disclosed herein.

Referring to FIG. 3A, the time domain packet structure includes a set of preambles. Each preamble is identical to one other preamble within the time domain packet structure of a preamble pair (ie, one of the preambles). Also, the preamble may refer to any pair of identical IQ sample sequences from which IQ sample sequences may be time separated. Also, the positions and lengths of the sequences must be known at the node 200. For example, the sequences may include a cyclic prefix in OFDM systems such as LTE, 5G new radios, Wi-Fi (802.11), xxxxxx preamble in Wi-Fi systems, and the like.

The preamble includes preamble pairs, for example P1, P2, P3, P4, P5, P6, P7 and P8, where a set of preamble pairs are identical. In other words, P1 is equal to P2, P3 is equal to P6, P5 is equal to P8 and P7 is equal to P4. In one embodiment, a set of preambles is represented as a preamble pair, and each preamble in the preamble pair is identical to at least one other preamble in the preamble structure. Identical preambles in the preamble structure enable cancellation of the received signal while determining self-interference channel estimates. In addition, each preamble is a complex number having a specific value according to each preamble.

The time domain packet structure (300) of the signal received by the node (200) includes a preamble (310) and a data block (320). The preamble 310 includes sequential preamble pairs where each preamble is identical to at least one other preamble in the preamble structure. The data block 320 includes data to be transmitted to the node 200 by the first UE 102a. The preamble 310 is used by the node 200 to extract data from the data block 320 of the time domain packet structure 300 of the received signal.

3B shows a process for obtaining a composite signal using the over-the-air self-interference signal and a received signal, in accordance with embodiments as disclosed herein.

Referring to FIG. 3B, the composite signal is obtained by adding the received signal to the self-interference signal. The received signal includes data along with the preamble 310. In one example, consider the preamble to include preamble pairs, eg P1, P2, P3, P4, P5, P6, P7 and P8, where successive preamble pairs are equal. In other words, P1 is equal to P2, P3 is equal to P4, P5 is equal to P6, and P7 is equal to P8. In another example, consider a preamble in the preamble pair to be equal to a different preamble in the preamble structure, where P1 is equal to P2, P3 is equal to P6, P5 is equal to P8 and P7 is equal to P4 .

The self-interference signal is denoted by SI in the time domain packet structure. SI1, SI2, SI3 and SI4 correspond to SI packets during P1, P2, P3 and P4, respectively.

CS1, CS2, CS3, and CS4 represent composite signals obtained from the transceiver 210 of the node 200.

Therefore, the values of CS1, CS2, CS3 and CS4 are calculated as follows.

CS1 = P1 + SI1;

CS2 = P2 + SI2;

CS3 = P3 + SI3, and

CS4 = P4 + SI4.

4 is a flow diagram 400 illustrating a method for decoding a signal received by a node 200 in an in-band full-duplex wireless communication system, in accordance with embodiments as disclosed herein.

Referring to FIG. 4A , at step 402 , the method includes receiving a signal from a first UE 102a. The received signal includes a set of preambles where each preamble is equal to at least one preamble in a preamble structure.

At step 404, the method includes obtaining a composite signal comprising a self-interference signal. The self-interference signal is known by the node 200 because the self-interference is caused by a signal transmitted by the second UE 102b to the second UE 102b. .

At step 406, the method includes determining a self-interference channel estimate using the composite signal. The self-interference channel estimates are obtained by determining differences between consecutive pairs of composite signal components in the composite signal. Also, the received signal is removed from the composite signal.

At step 408, the method includes decoding the received signal by canceling the self-interference signal from the received signal. The self-interference signal is canceled based on the self-interference channel estimation. The self-interfering channel estimates are used to cancel self-interfering signals that interfere with decoding of the received signal. Thus, a better quality of the received signal is obtained and the data is decoded accordingly.

The various actions, actions, blocks, steps, etc. of the method may be performed in the order presented, in a different order or concurrently. Also, in some embodiments, some of the actions, operations, blocks, steps, etc. may be omitted, added, modified, skipped, etc. without departing from the scope of the present invention.

5 is a block diagram showing various elements of a UE 500, according to embodiments as disclosed herein.

Referring to FIG. 5 , the UE 500 may include a transceiver 510 , an encoder/decoder 520 , a processor 530 and a memory 540 .

In one embodiment, the transceiver 510 may be configured to transmit a signal to the node 200 . The signal to be transmitted includes encoded data along with the preamble structure 310 . The transceiver 510 may also be configured to receive signals transmitted by the node.

In one embodiment, the encoder 520 may be configured to provide a preamble structure 310 to a signal to be transmitted to the node 200. The preamble structure 310 includes a set of preambles where each preamble is equal to at least one preamble in the preamble structure. Also, the preamble 310 is used for self-interference cancellation by the node 200 .

In one embodiment, the processor 530 interacts with hardware elements such as the transceiver 510, the encoder 520, and the memory 540 in the UE 500 to transmit information to the node 200. It can be configured to provide a preamble structure 310 that is symmetrical to the signal.

In one embodiment, the memory 540 may include non-volatile storage elements. Examples of such non-volatile storage elements may include magnetic hard disks, optical disks, floppy disks, flash memories, or forms of Electrically Programmable Memory (EPROM) or Electrically Erasable and Programmable Memory (EEPROM). Also, the memory 540 may be considered a non-transitory storage medium in some examples. The term “non-transitory” may indicate that the storage medium is not implemented as a carrier wave or a propagating signal. However, the term “non-transitory” should not be construed as meaning that memory 540 is not removable. In some examples, the memory 540 may be configured to store a larger amount of information than the memory. In certain examples, the non-transitory storage medium may store data that may change over time (eg, in random access memory (RAM) or cache).

6 is a flowchart 600 showing a method for transmitting a signal by the UE 500 in an in-band full-duplex wireless communication system according to embodiments as disclosed herein.

Referring to Figure 6, at step 602, the method includes providing a preamble structure to a signal to be transmitted and encoding data by the first UE 102a. The signal to be transmitted includes a set of preambles. Also, each preamble is identical to at least one preamble in the preamble structure.

At step 604, the method includes transmitting data encoded by the first UE 102a to the node. The first UE 102a transmits a signal to be transmitted to a node through an RF channel. The signal to be transmitted may be an RF analog signal or a baseband digital signal.

The various actions, actions, blocks, steps, etc. of the method may be performed in the order presented, in a different order or concurrently. Also, in some embodiments, some of the actions, operations, blocks, steps, etc. may be omitted, added, modified, skipped, etc. without departing from the scope of the present invention.

7 is a diagram showing self-interference channel estimation according to embodiments as disclosed herein.

Referring to Figure 7, the self-interference channel estimates are obtained by determining the difference between successive pairs in a composite signal that cancels the received signal. The adaptive filter is used to determine self-interfering channel estimates.

The adaptive filter employs Active Noise Control (ANC), also known as noise cancellation or Active Noise Reduction (ANR), to cancel self-interference signals to decode the received signal. . The ANC is a method of reducing a noise signal by adding a second signal specially designed to cancel the noise signal. In the proposed method, the noise signal is a self-interference signal and the second signal specially designed to cancel the noise signal is a received signal having a preamble 310 specifically for canceling the self-interference signal.

In addition, the self-interference channel estimation is determined as follows:

CS1 = P1 + SI1 and CS2 = P2 + SI2

Also, intermediate values are calculated and then the intermediate values are used to determine the self-interference channel estimates.

Median value 1 = CS1-CS2

= P1 + SI1 - (P2 + SI2)

=(P1-P2) + (SI1-SI2)

If the two preambles are the same, that is, if P1 = P2 and P1 - P2 = 0

Median 1 = SI1- SI2;

Intermediate 2 = CS3 - CS8

= P3 + SI3 - (P8 + SI8)

=(P3 - P8) + (SI3 - SI8)

For P3 = P8 and P3-P8 = 0 in the representative preamble structure P1XXXXXXP8

Median 2 = SI3 - SI8.

Therefore, the calculated intermediate values are used to determine a self-interference channel estimate having only self-interference channel components when the received signal components are canceled. Removal of the received signal component from the composite signal provides better channel estimates. It should be noted here that the number of samples required for channel estimation does not depend on the received signal strength.

The foregoing description of specific embodiments sufficiently conveys the general nature of the embodiments herein so that others, by applying current knowledge, may readily modify or adapt the specific embodiments for various applications without departing from the general concept. It is intended that disclosures and such modifications and variations be understood within the meaning and scope of the disclosed embodiments. It should be understood that the phraseology or terminology employed herein is for the purpose of description and is not intended to be limiting. Therefore, although the embodiments herein have been described in terms of preferred embodiments, those skilled in the art will recognize that the embodiments herein may be practiced with modifications within the spirit and scope of the embodiments as described herein. .

Claims (8)

A method for decoding a signal received by a node in a wireless communication system, comprising:
The method,
receiving, by the node, a signal from a first User Equipment (UE), the received signal comprising encoded data and a symmetric preamble structure, the symmetric preamble structure comprising a set of preambles; and each preamble is equal to at least one preamble in the symmetric preamble structure;
obtaining a composite signal comprising a self-interference signal and the received signal, wherein the composite signal is obtained when the received signal is added to the self-interference signal over the air and the self-interference signal is obtained at the node Known from -;
determining, by the node, a difference between successive preambles in the composite signal using an adaptive filter;
determining a self-interference channel estimate using the composite signal based on differences between successive preambles in the composite signal; and
based on the self-interference channel estimate, decoding the received signal by canceling the self-interference signal from the received signal;
A decoding method of a signal received by a node in a wireless communication system, including a. According to claim 1,
wherein the self-interference channel estimate is determined by finding differences between identical preambles in the composite signal using an adaptive filter. According to claim 1,
wherein the self-interference channel estimate is determined using an adaptive filter. According to claim 1,
wherein the preamble is part of a signal received at the node from the UE. In a node for decoding a signal received in a wireless communication system,
The node is
processor;
a memory coupled to the processor;
a transceiver coupled to the processor and the memory;
Including,
The transceiver,
configured to receive a signal from a first user equipment (UE), the received signal including encoded data and a symmetric preamble structure, the symmetric preamble structure including a set of preambles, each preamble comprising the identical to at least one preamble in the symmetric preamble structure;
The transceiver,
and obtain a composite signal comprising a self-interference signal and the received signal, wherein the composite signal is obtained when the received signal is added to the self-interference signal over the air, and the self-interference signal comprises the is known from the node,
The transceiver,
determine a difference between successive preambles in the composite signal using an adaptive filter;
The transceiver,
determine a self-interference channel estimate using the composite signal based on a difference between successive preambles in the composite signal;
The transceiver,
and based on the self-interference channel estimate, decode the received signal by canceling a self-interference signal from the received signal. According to claim 5,
wherein the self-interference channel estimate is determined by finding differences between identical pairs in the composite signal using an adaptive filter. According to claim 5,
wherein the self-interference channel estimate is determined using an adaptive filter. According to claim 5,
and the preamble is part of a signal received at the node from the UE.

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